Application of nanocomposite cellulose fibers with luminescent properties to paper functionalization

Cellulose fibres modified with the luminescent inorganic compound were obtained by using N-methylmorpholine-N-oxide as a direct solvent. The fibres were cut and introduced to the unrefined and refined paper pulp samples. Schopper-Riegler value of the pulps were measured and the laboratory paper samples were formed. Observations under UV radiation showed that the cellulose luminescent fibres were randomly and even scattered in the paper and were well visible. Measurements of the paper properties such as tensile index, Elmendorf tear resistance, Bendtsen air permeability, Bendtsen roughness, folding endurance, bursting strength and tensile energy absorption were carried out and the scanning electron microscopy (SEM) analysis was used for the assessment of the paper structure and the bonding properties of the luminescent fibres. SEM analysis showed that the cellulose man-made fibres create microfibril network and have excellent compatibility with the paper. The results showed that cellulose man-made fibres with luminescent properties express similar properties to natural cellulose fibres (e.g. external fibrillation and bonding properties) which are useful for the purpose of secure paper production. Cellulose man-made fibres introduced to the paper do not have any disadvantageous impact on paper properties.